Software References

A new field in the MetaData sections, that allows to add the Software that was used to create the Phenopacket.
This could be tools like Phenoboard, Phenoxtract or LLM models.

The field should at least contain the values name: string, version: string, url/repository: string.

Start by reading the existing MetaData sections and their field conventions in the phenopacket schema. Define the software-reference field with name, version, and URL or repository values, then verify that the schema represents the requested metadata consistently with nearby fields.

Written by the indexing model from the issue text.